Combustion kinetics of conventional and alternative jet fuels using a hybrid chemistry (HyChem) approach

With increasing use of alternative fuels, approaches that can efficiently model their combustion chemistry are essential to facilitate their utilization. The hybrid chemistry (HyChem) method incorporates a basic understanding about the combustion chemistry of multicomponent liquid fuels that overcomes some of the limitations of the surrogate fuel approach. The present work focused on a comparative study of one conventional, petroleum-derived Jet A fuel (designated as A2), with an alternative, bio-derived fuel (designated as C1), using a variety of experimental techniques as well as HyChem modeling. While A2 is composed of a mixture of n-, iso-, and cyclo-alkanes, and aromatics, C1 is composed primarily of two highly branched C12 and C16 alkanes. Upon decomposition, A2 produces primarily ethylene and propene, while C1 produces mostly isobutene. HyChem models were developed for each fuel, using both shock tube and flow reactor speciation data. The developed models were tested against a wide range of experimental data, including shock tube ignition delay time and laminar flame speed. The stringent validations and agreement between the models and experimental measurements highlight the validity as well as potential wider applications of the HyChem concept in studying combustion chemistry of liquid hydrocarbon fuels.